两段类似的代码，但其中一段不起作用（Bokeh for Python）

Question

我在 python 中有两个不同但相似的代码，它们使用 Bokeh 来制作交互式绘图。下面的代码工作正常（我在网上找到的）。

import numpy as np

from bokeh.layouts import column, row
from bokeh.models import ColumnDataSource, CustomJS, Slider
from bokeh.plotting import figure, show

x = np.linspace(0, 10, 500)
y = np.sin(x)

source = ColumnDataSource(data=dict(x=x, y=y))

plot = figure(y_range=(-10, 10), width=400, height=400)

plot.line('x', 'y', source=source, line_width=3, line_alpha=0.6)

amp = Slider(start=0.1, end=10, value=1, step=.1, title="Amplitude")
freq = Slider(start=0.1, end=10, value=1, step=.1, title="Frequency")
phase = Slider(start=-6.4, end=6.4, value=0, step=.1, title="Phase")
offset = Slider(start=-9, end=9, value=0, step=.1, title="Offset")

callback = CustomJS(args=dict(source=source, amp=amp, freq=freq, phase=phase, offset=offset),
                    code="""
    const A = amp.value
    const k = freq.value
    const phi = phase.value
    const B = offset.value

    const x = source.data.x
    const y = Array.from(x, (x) => B + A*Math.sin(k*x+phi))
    source.data = { x, y }
""")

amp.js_on_change('value', callback)
freq.js_on_change('value', callback)
phase.js_on_change('value', callback)
offset.js_on_change('value', callback)

show(row(plot, column(amp, freq, phase, offset)))

然而，下一个确实产生了一个绘图，但滑块没有响应。

import numpy as np

from bokeh.layouts import column, row
from bokeh.models import ColumnDataSource, CustomJS, Slider
from bokeh.plotting import figure, show

x = np.linspace(0, 10, 500)
y = np.sin(x)

source = ColumnDataSource(data=dict(x=x, y=y))

plot = figure(y_range=(-10, 10), width=400, height=400)

plot.line('x', 'y', source=source, line_width=3, line_alpha=0.6)

amp1 = Slider(start=0, end=10, value=1, step=.1, title="Amplitude 1")
amp2 = Slider(start=0, end=10, value=0, step=.1, title="Amplitude 2")
freq1 = Slider(start=0, end=10, value=1, step=.1, title="Frequency 1")
freq2 = Slider(start=0, end=10, value=0, step=.1, title="Frequency 2")
phase1 = Slider(start=-6.4, end=6.4, value=0, step=.1, title="Phase 1")
phase2 = Slider(start=-6.4, end=6.4, value=0, step=.1, title="Phase 2")
offset1 = Slider(start=-9, end=9, value=0, step=.1, title="Offset 1")
offset2 = Slider(start=-9, end=9, value=0, step=.1, title="Offset 2")

callback = CustomJS(args=dict(source=source, amp1=amp1, freq1=freq1, phase1=phase1, offset1=offset1, amp2=amp2, freq2=freq2, phase2=phase2, offset2=offset2),
                    code="""
    const A = amp1.value
    const AA = amp2.value
    const f = freq1.value
    const ff = freq2.value
    const phi = phase1.value
    const phiphi = phase2.value
    const B = offset1.value
    const BB = offset3.value

    const x = source.data.x
    const y = Array.from(x, (x) => A*Math.sin(f*x+phi)+AA*Math.sin(ff*x+phiphi)+B+BB)
    source.data = { x, y }
""")

amp1.js_on_change('value', callback)
freq1.js_on_change('value', callback)
phase1.js_on_change('value', callback)
offset1.js_on_change('value', callback)
amp2.js_on_change('value', callback)
freq2.js_on_change('value', callback)
phase2.js_on_change('value', callback)
offset2.js_on_change('value', callback)

show(row(plot, column(amp1, freq1, phase1, offset1, amp2, freq2, phase2, offset2)))

第二个绘制的函数有点复杂，但应该可以工作。为什么不起作用？

除了检查代码是否有拼写错误之外，我真的没有什么可以尝试的。

Answer 1

在第二次代码更改中

const BB = offset3.value

到

const BB = offset2.value